fregIDE is an Eclipse plugin that supports the frege programming language.
You can install or upgrade fregIDE from the installation/upgrade site at http://www.frege-lang.org/fregide/.
UPDATE It has come to my attention that the link above seems to have problems at times, like
- eclipse complains it is not an update site
- the download goes very slow and even times out (see also Issue#10)
If you experience the same, try this alternative URL.
Please also read the tutorial that describes the installation in detail.